It finally emerged as a complete redesign of the Soyuz in the late seventies. The Soyuz T introduced a revised Igla rendezvous system and a new service module with unitary translation / attitude control thrusters as part of a single bipropellant system with the main pump-fed engine. Solar panels were reintroduced; the fuel load was increased; and all new digital avionics were developed. Crew safety was improved with a new launch escape system and accommodation was provided for the first time for a three-man crew in spacesuits.

The USSR Defense Ministry issued a requirement for an "Orbital Research Station" (OIS) in March 1967 (reaffirmed in the decree of May 1968). This small station was to operate at an inclination of 51.6 degrees, an altitude of 250-270km, and have a flight duration of 30 days. Kozlov's Kuibyshev Branch of the former OKB-1 delivered a proposal for a Soyuz VI (7K-VI) complex in November 1967. (Not to be confused with the quite different Soyuz VI developed by Kozlov in the 1965-1967 period).

The new Soyuz was called by the OKB the 7K-S, and given the article number 11F732 by the military. The Soyuz-VI (abbreviation for military research) complex would consist of the OIS (with 700 to 1,000 kg of scientific equipment) and the Soyuz 7K-S. The Soyuz would have a crew if two, a probe-drogue docking system and an internal transfer tunnel.

The draft design for the OIS was released on 21 June 1968, followed by that for the 7K-S on 14 October 1968. Drawing release began in 1969. The OIS was cancelled in February 1970 after the start of the Salyut project. The Soyuz 7K-S, however continued in two parallel designs - the base variant, which was for special-purpose solo missions; and a space station transport variant 7K-ST. The revised designs for the 7K-S were completed on 11 August 1972.

The initial Soyuz 7K-S program was to consist of four unmanned, followed by two manned test flights, then two operational launches. Cosmonauts (among them Lyakhov and Voronov ) were assigned to the project in 1973. A State Commission was formed on 21 June 1974 to oversee the flight tests.

The draft design for 7K-ST space station transport version was completed in August 1974.

After the fourth N1 launch failure, a major reorganization of Soviet space enterprises was undertaken. Mishin was fired as head of the former OKB-1. After Kozlov turned down the job, Glushko was made head of a newly formed NPO Energia, combining OKB-1 and Glushko's Energomash engine production OKB. The 7K-S was cancelled; experiments planned for the 7K-S solo flights were transferred to the Salyut program.

Development of the launch escape system for 7K-S had run from 1968 to 1972. The new design was used for Soyuz Apollo-Soyuz Test Project version.

At the time the Soyuz 7K-S was cancelled, one of the uncrewed test vehicles was already at Tyuratam being prepared for launch. The first three were launched unmanned as technology tests - Cosmos 670 (7K-S No.1), Cosmos 772 (7K-S No.2), and Cosmos 869 (7K-S No.3).

The Soyuz 7K-ST transport project continued, except now being redesigned for a crew of three. The revised design for the new version was issued in 1975; and the first Soyuz T flew in 1978 as Cosmos 1001. The basic Soyuz T was adapted in the TM version for use with the Mir space station, and it would continue in use into the 21st Century as the Assured Crew Rescue Vehicle for the International Space Station.

Soyuz The Russian Soyuz spacecraft has been the longest-lived, most adaptable, and most successful manned spacecraft design. In production for fifty years, more than 240 have been built and flown on a wide range of missions. The design will remain in use with the international space station well into the 21st century, providing the only manned access to the station after the retirement of the shuttle in 2011. More...

Soyuz Russian orbital launch vehicle. The world's first ICBM became the most often used and most reliable launch vehicle in history. The original core+four strap-on booster missile had a small third stage added to produce the Vostok launch vehicle, with a payload of 5 metric tons. Addition of a larger third stage produced the Voskhod/Soyuz vehicle, with a payload over 6 metric tons. Using this with a fourth stage, the resulting Molniya booster placed communications satellites and early lunar and planetary probes in higher energy trajectories. By the year 2000 over 1,628 had been launched with an unmatched success rate of 97.5% for production models. Improved models providing commercial launch services for international customers entered service in the new millenium, and a new launch pad at Kourou was to be inaugurated in 2009. It appeared that the R-7 could easily still be in service 70 years after its first launch. More...

Soyuz 11A511U Russian standardised man-rated orbital launch vehicle derived from the original R-7 ICBM of 1957. It has been launched in greater numbers than any orbital launch vehicle in history. Not coincidentally, it has been the most reliable as well. After over 40 years service in Russia, ESA built a new launch pad at Kourou which will keep it in service from three launch sites in three countries well into the mid-21st Century. More...

Soyuz 11A511U2 Russian orbital launch vehicle. Soyuz 11A511U2 used synthetic kerosene ('Sintin') in first stage for launch of premium reconnaisance satellite and manned payloads requiring just a bit more payload than the standard 11A511 could offer. Further use of the 11A511U2 abandoned in 1996 due to Sintin production stoppage. Later Soyuz spacecraft launched on standard Soyuz, with reduced payload and rendezvous with Mir in lower orbit accepted. More...

Mir The Mir space station was the last remnant of the once mighty Soviet space programme. It was built to last only five years, and was to have been composed of modules launched by Proton and Buran/Energia launch vehicles. These modules were derived from those originally designed by Chelomei in the 1960's for the Almaz military station programme. As the Soviet Union collapsed Mir stayed in orbit, but the final modules were years late and could only be completed with American financial assistance. Kept flying over a decade beyond its rated life, Mir proved a source of pride to the Russian people and proved the ability of their cosmonauts and engineers to improvise and keep operations going despite all manner of challenges and mishaps. More...

Salyut 6 Mishin was authorised in December 1973 to build an improved design DOS-5 version of the Salyut station using Almaz facilities. Mishin's bureau borrowed the two docking port configuration of Chelomei's Almaz OPS-2 This station's second docking port would allow rotation of crews and resupply/refueling using unmanned Progress spacecraft. More...

Salyut 7 Due to cancellation of the Almaz military station, and delays in the Mir project, the decision was taken in the late 1970's to fly the back-up to DOS-5 / Salyut 6. This was launched as Salyut 7 in 1982. The opportunity was still taken to fly 'guest cosmonauts' from friendly countries on short visits to the stations, although emphasis was placed on military experiments. Salyut 7 was able to conduct significant military experiments thanks to the greatly increased volume and payload of the TKS modules diverted from the Almaz programme that docked with the station. More...

Associated Propellants

N2O4/UDMH Nitrogen tetroxide became the storable liquid propellant of choice from the late 1950's. Unsymmetrical Dimethylhydrazine ((CH3)2NNH2) became the storable liquid fuel of choice by the mid-1950's. Development of UDMH in the Soviet Union began in 1949. It is used in virtually all storable liquid rocket engines except for some orbital manoeuvring engines in the United States, where MMH has been preferred due to a slightly higher density and performance. More...

Baikonur Russia's largest cosmodrome, the only one used for manned launches and with facilities for the larger Proton, N1, and Energia launch vehicles. The spaceport ended up on foreign soil after the break-up of Soviet Union. The official designations NIIP-5 and GIK-5 are used in official Soviet histories. It was also universally referred to as Tyuratam by both Soviet military staff and engineers, and the US intelligence agencies. Since the dissolution of the Soviet Union the Russian Federation has insisted on continued use of the old Soviet 'public' name of Baikonur. In its Kazakh (Kazak) version this is rendered Baykonur. More...

Soyuz 7K-S cancelled; Soyuz 7K-ST continued - .
Nation: USSR. Spacecraft: Soyuz 7K-S; Soyuz OB-VI; Soyuz T. The 7K-S was cancelled at the same time as the N1 and the reorganisation of the space industry. Experiments planned for the solo flights were transferred to the Salyut program. The first test vehicle was already at Baikonur being prepared for launch. It was decided to launch the first three unmanned as technology tests - Cosmos 670 (7K-S No.1), Cosmos 772 (7K-S No.2), and Cosmos 869 (7K-S No.3). The Soyuz 7K-ST transport project continued, except now being redesigned for a crew of three. The 7K-ST would eventually fly as the Soyuz T and Soyuz TM ferry to the Salyut 7 and Mir space stations.